Hi,
Can any one help me?

i opened up the fob on my space key to change what i thought was a dead battery,thats when i found out the owner before me had ripped the battery holder off the printed board and tryed to solder/glue it back together.

can some one please tell me if i can buy a used fob and programe it to the car by my self or do i need to go pay big bucks at my local dealer?

ps: my car is a 03 facelift 2.2 auto cdx with factory alarm.
i look forward to your help